The present invention relates to a bushing for reducing lateral looseness in a pivot system and in particular for use in a seat assembly in which a seat back is pivotally mounted to a lower seat cushion where the bushing is used to reduce lateral looseness of the seat back relative to the seat cushion.
Many seat assemblies, particularly automobile seat assemblies, are equipped with a reclining seat back that is pivotally mounted to a lower seat cushion. In a typical seat assembly structure, the seat cushion frame on both lateral sides of the seat cushion includes a pair of spaced plate members with the seat back frame having a downwardly extending plate member positioned between the two plates on both sides of the seat assembly. A pin carried by the spaced plate members of the seat cushion frame forms a pivot about which the seat back frame is rotated.
In many seat assemblies, a bushing is placed on the pivot pin between the back frame and one plate of the cushion frame to hold the seat back frame against the opposing plate of the seat cushion frame. These bushings are either made of metal or plastic and provide a small clearance between the bushing and the frame members to enable proper operation of the seat back recliner without binding. However, this small clearance allows for lateral movement of the back frame relative to the seat cushion frame The looseness from this clearance can result in both seat back shake as well as a feeling of instability during a vehicle cornering operation.
Accordingly, it is an object of the present invention to provide a bushing for a pivot system that reduces this lateral looseness.
It is a feature of the present invention to provide a bushing made from a cylindrical nylon body which has an interference fit between the back frame and the cushion frame. The lubricity of the nylon plus the compressibility of the nylon allows the bushing to be used in an interference fit while not exhibiting either excessive wear or binding in operation of the seat back recliner.
It is a further feature of the present invention to enlarge the diameter of the bushing through passage at the ends of the bushing to form an annular space between the bushing and the pivot pin at the bushing ends.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection wit the accompanying drawings.